MELBOURNE - Sebastian Vettel is convinced Ferrari have a better car than the one that stuttered through a winless season last year but has played down his team's chances of upsetting Mercedes at Sunday's season-opening Australian Grand Prix.

The four-times world champion has joined Kimi Raikkonen at Formula One's glamour team and has also something to prove after failing to win a race in his final season with Red Bull.

Ferrari enjoyed a solid winter testing but constructors' champions Mercedes set the benchmark and are tipped to carry their dominance into Sunday's race at Albert Park.

"I didn't try last year's car but I think it's a step forward," Vettel told reporters in Melbourne on Thursday.

"In fact, compared to where I was last year, it really feels like a good car. I think people have been pushing on all fronts trying to improve and so far they've succeeded but equally we know we have work to do.

"I think it would be a bit too aggressive [to say that]," Vettel added, when asked whether Ferrari could beat Mercedes in Melbourne.

"I think we have to keep our feet on the ground. After winter testing it will be interesting to find out where we are, to find out where we are compared to other people. The most important is we have a solid start and work from there.

"We need to go step-by-step."

Dressed in Ferrari red and sporting a new cropped haircut, the 27-year-old arrives at Albert Park as just one of the chasing pack, a new feeling after three consecutive years as defending champion with Red Bull.

Fitting into the Maranello way of doing things had been "fun", said the German, but there was plenty more to learn.

"Every team has got it's own way to operate and to work," he said. "There's a lot of stuff I've had to get used to and still probably have to.

"I need to get to know the team better and the team to know me which will still probably take some time."

Vettel has replaced twice world champion Fernando Alonso, now departed for McLaren, to join up with 2007 world champion Raikkonen, nicknamed 'Ice Man'.

How the new pair interact will be closely watched at Melbourne and Vettel joked when asked whether he was friendly with the Finn.

"It depends on your understanding of friends," he said.

"I don't expect any difficulties on a personal level. I'm sure we'll try to beat each other on the track."